In a signal transmission system, whether the signal transmission medium be wire or optical fibers, there are, of necessity, interruptions such as splices, for example. In general, in the prior art, such splices are enclosed in a splice closure module for protection, wherein large numbers of splices are housed and, to a large extent, protected from the environment and from other damaging factors, such as from lightning or from various gnawing animals. Where conditions are likely to be extreme, it has been the practice to enclose a splice closure within a protective shell and, often, to fill the empty volume within the shell with encapsulant.
In the area of fiber optics, the splice closure module preferably comprises a metallic body having entrances at each end for the ingress and egress of optical fiber cables to be spliced together. Within the closure, the cables are stripped to the individual fibers for splicing, and the splices are generally organized and protected by means of a splice tray. One such closure is the AT&T UCB1, which, with the proper component parts, anchors and seals the cables, routes the cable fibers to the splice tray, and supports the splice tray itself. Sealant is used around the periphery and in the opening to seal the closure so that the splices are protected from mechanical shock, displacement, or breakage, as well as from moisture and the like. In U.S. patent application Ser. No. 08/263,645, filed Jun. 22, 1994, of Denis E. Burek, Marc D. Jones, Wesley W. Jones and Phillip M. Thomas, the UCB1 closure is shown, along with the several components for achieving the ends discussed heretofore. Another type of splice closure is shown in U.S. Pat. No. 5,185,845 of Wesley W. Jones. In both types of closures, as well as in most other types, it is a necessary feature that the closure be re-entrant. That is, it must be amenable to being entered so that work may be performed on the splices themselves, or so that damaged or malfunctioning parts may be replaced. As a consequence of the need for re-entry, the splice closure itself cannot be filled with an encapsulant which would insure substantially complete protection. It has been the practice, as pointed out in the foregoing, to enclose the splice closure within a shell which can then be filled with a protective material.
In prior art arrangements, the outer protective shell which encloses the splice closure or other type of assembly is filled with an insulating liquid curable encapsulant. The shell must, of course, be substantially leak tight so that the encapsulant, in its liquid phase, does not leak out prior to hardening. The liquid encapsulant is generally poured into the shell and it flows to fill the voids within the shell so as to surround the closure. However, even in its liquid phase the encapsulant is not free flowing because of its high viscosity. As a consequence, air pockets and other voids often remain after the encapsulant hardens, and thus insufficient protection of the closure results. Often such voids occur around the cables entering and leaving the shell and thus water, for example, has almost a clear pathway along the cables themselves directly to the region that is most in need of protection. In U.S. Pat. No. 4,875,952 of Mullin et al., there is shown an encapsulating arrangement that overcomes the problems of the prior art, in which the encapsulant is introduced under pressure into an elastic bladder surrounding the splice tray, and then an additional amount of encapsulant is forced into the surrounding protective shell. Such an arrangement effectively protects the splices or other connectors, but re-entry is made difficult by the splices and wires being embedded in the encapsulant. In U.S. Pat. No. 4,692,564 of Campbell, et al. there is shown an arrangement that is somewhat similar to the arrangement of the Mullin et al. arrangement, but where the encapsulant can be either gravity fed or fed under pressure. The outer cover or shell of the Campbell et al. arrangement comprises two substantially identical members having flanges along their edges and which are fastened together by means of C-clamps.
In use, it is often desirable or where necessary that the entire assembly of cables, closure and protective shell be suspended from an overhead support strand, wire rope or for interior mounting, a support bar. This can be, and most often is, accomplished by the use of straps surrounding the shell and attached to the support stand. Such lashing of the assembly produces the desired suspension, but can be both awkward and time consuming which, in turn, can be costly.